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Biomedical subjects

S Y Ho

Publications and source records attributed to S Y Ho.

At least 271 records · Page 15Linked to original sources
PubMed1986

Anatomy of congenital complete heart block and relation to maternal anti-Ro antibodies.

The anatomy of the conduction system was studied in 8 patients who had isolated congenital complete heart block. Atrial-axis discontinuity was seen in 7 hearts from children born to mothers with anti-Ro antibodies. The anticipated area of the atrioventricular node was occupied by fibrous and adipose tissue. The heart from the only child whose maternal serum was anti-Ro negative had nodoventricular discontinuity of the conduction system. This difference in anatomy may have etiologic significance.

Antibodies↗
PubMed1986

Diagnosis and significance of atrial isomerism.

Fifty-one patients at the Brompton Hospital were identified as having either right or left atrial isomerism by reviewing the records and catheterization, echocardiographic and, in 17 cases, autopsy data. Every study patient had 1 or more of the following conditions: isomeric bronchial anatomy; angiographic or necropsy evidence of atrial anatomy; echocardiographic diagnosis of isomerism; and anomalies of systemic or pulmonary venous connection. Patients with anomalous venous connections all had additional signs of isomerism. Neither right nor left type was predominant in either sex. The heart was in the left chest slightly more often than the right. Abdominal visceral heterotaxy was the most frequent radiographic finding. An ambiguous and biventricular connection was the commonest type of atrioventricular (AV) connection in left isomerism. A common AV valve was the most frequent mode of connection in both forms. Univentricular AV connection, double-outlet right ventricle, pulmonary atresia and discordant ventriculoarterial connection were commoner in right isomerism. Left isomerism is associated with much longer survival, its constellation of associated malformations frequently being less severe and more amenable to corrective surgery. A precise diagnosis must be made during life in order to select the most appropriate treatment.

Bronchi↗
PubMed1986

Zinc in multiple sclerosis. II: Correlation with disease activity and elevated plasma membrane-bound zinc in erythrocytes from patients with multiple sclerosis.

Previous studies have shown that zinc levels in erythrocytes are significantly elevated in patients with multiple sclerosis (MS). To examine the correlation between erythrocyte Zn levels and disease activity, we measured erythrocyte Zn levels longitudinally. Levels were dramatically decreased during a clinically documented exacerbation of MS. To determine the localization of increased Zn levels in MS erythrocytes, we employed standard techniques for the isolation of nonhemoglobin erythrocyte membrane ghosts. Patients with MS had three times more Zn in ghost material than did controls. Chloroform-methanol extraction in erythrocyte ghosts followed by determination of Zn levels indicated that most of the membrane-bound Zn was associated with the lipid-soluble fraction. Non-lipid-associated Zn and total membrane protein concentration were similar in MS and control samples. Results suggest that mechanisms which govern cellular availability, compartmentalization of Zn, or the binding of Zn to cell surface membranes may be altered in patients with MS, and that these mechanisms vary with disease activity.

Adult↗
PubMed1986

Absent aortic valve leaflets.

A newborn with difficulty in feeding and with tachypnoea was admitted to the hospital. During the following days his condition deteriorated and he died at the age of 8 days. At autopsy we found an unusual association of hypoplastic left heart syndrome and absence of the aortic leaflets.

Aortic Valve↗
PubMed1986

Coronary arteries in complete transposition: the significance of the sinus node artery.

Hearts from 29 children with complete transposition were examined postmortem to analyze the pattern of the coronary arteries and the origin of the sinus node artery. Four patterns of origin and distribution of the coronary arteries were found. In all, the coronary arteries arose from one or both of the facing sinuses, which were termed sinus 1 and sinus 2. The patterns were left coronary artery from sinus 1 and right coronary artery from sinus 2; anterior descending artery from sinus 1 and right coronary artery and circumflex artery from sinus 2; left coronary and right coronary from sinus 2; and circumflex artery from sinus 2 and right coronary artery from sinus 1. This study highlights the patterns of the coronary arteries in complete transposition and categorizes the variability using a simple classification. It also emphasizes the surgical significance of variations in distribution of the sinus node artery.

Autopsy↗
PubMed1986

Ostium primum atrioventricular septal defect: an anatomical and surgical review.

The results of surgical repair of ostium primum atrioventricular septal defect show continued improvement. This improvement reflects the advances in open-heart surgery in general and, in particular, the better understanding of the anatomy of the conduction tissue and the morphology and function of the left atrioventricular valve. We have corrected this defect in 84 patients over a ten-year period. There were 2 early deaths (2.4%) and 2 late deaths (2.4%). Two patients had problems related to conduction. Our surgical approach has been to place the interatrial baffle in such a way as to avoid the displaced atrioventricular node and thereby leave the coronary sinus in the left atrium. Our approach to repair of the so-called cleft in the left atrioventricular valve (in reality the space between the ventricular components of the bridging leaflets), is based on the unequivocal triple-leaflet morphology of this valve.

Adolescent↗
PubMed1986

The surgical anatomy of the left ventricular outflow tract in atrioventricular septal defect.

The left ventricular (LV) outflow tract (OT) in atrioventricular (AV) septal defect is an important structure that paradoxically is hardly ever seen by a surgeon. The LVOT is prone to develop obstruction following surgical procedures, such as left AV valve replacement, that seemingly do not affect the LVOT itself. We examined 15 hearts with AV septal defects and noted the anatomical boundaries of the LVOT. Additionally, the LVOT was examined microscopically, and it was sectioned to replicate echocardiographic images. A sham operation was performed to show the extent of the proposed resection for AV valve replacement. The mean length of this area was 91.8 +/- 35.5% (range, 28.6 to 167.0%) of the diameter of the ascending aorta in our specimens of the Rastelli A variety. The mean diameter of the LVOT was 68.2 +/- 13.5% (range, 42.9 to 100.0%) of the diameter of the ascending aorta. The posterior wall of the OT can either be resected or widened. Resection seems to be opportune at AV valve replacement, whereas widening could be performed when the OT is intrinsically stenotic. When one fully appreciates the concept of a five-leaflet common valve, it is clear that the length of the OT depends on the extent of adherence between the superior bridging leaflet and the septal crest. In hearts that have two separate AV valve orifices, the OT is fully developed; there is no potential for interventricular shunting ("ostium primum defect"), because the superior bridging leaflet is always tightly adherent to the septal crest. AV valve replacement in these cases is especially hazardous.(ABSTRACT TRUNCATED AT 250 WORDS)

Aorta, Thoracic↗
PubMed1986

Aortic root pathology and sudden death in youth: review of anatomical varieties.

Post-mortem findings in 6 young people who died suddenly are reported; ages ranged from 9 to 28 years (average 17). All had practised sport, and 2 died during strenuous exercise. Three cases had been under observation for mild aortic stenosis, while no cardiovascular disorders had been suspected in the others. Autopsy studies ruled out coronary atherosclerotic diseases, myocardial disarray or myocarditis as well as any extracardiac cause of death in every case. A stenotic bicuspid aortic valve was found in 2; supravalvar aortic stenosis and incomplete isolation of the left coronary ostium in 1; anomalous origin of the right coronary artery from the left sinus of Valsalva in 1, and dissecting aneurysm of the ascending aorta in 2. These findings show that congenital anomalies of the aortic root (valve, wall, coronary ostia) are at risk for abrupt complications. Early detection of this frequently silent pathology by non-invasive techniques is mandatory to avoid effort and sporting activities and thus prevent sudden death.

Adolescent↗
PubMed1985

Morphological observations following "anatomical correction" for abnormal ventriculo-arterial connection.

Seven postmortem hearts from children who underwent anatomical correction for complete transposition (6 cases) and double outlet right ventricle (1 case) were examined in order to gain a better understanding of the pathological morphology in relation to the surgical procedure. Associated malformations were ventricular septal defect in all, patient arterial duct in 4 and aortic coarctation in 3. In all hearts the coronary arteries arose from the facing aortic sinuses and were relocated into the facing sinuses of the pulmonary trunk with minimal displacement. The orifices of the coronary arteries were reduced in caliber in one case. The sinus node artery arising from a lateral atrial artery was transected in one case. The Lecompte maneuver was performed in 4 cases and tension on the pulmonary trunk was observed in 2 cases. Potential right ventricular outflow tract obstruction was evident in all (including one in which it had been resected during surgery). The substrates of obstruction were anomalous parietal insertion of the outlet septum (2 cases), anomalous muscular trabeculation (1 case), rightward displacement of the outlet septum (1 case), parietal insertion of the outlet septum (1 case) and restrictive muscular infundibulum (1 case--DORV). In addition, all the complete transposition cases had hypertrophy of the parietal right ventricular wall. This study highlighted the anatomical features which could lead to poor results in the anatomical correction procedure. Some of the potential problems could be avoided by minor modifications to the technique.

Female↗
PubMed1985

Heart block and atrioventricular septal defect.

The cardiac conduction system was examined in 2 hearts which had repair of atrioventricular septal defect. The first was from a child known to have had a prolonged P-R interval and the second was from a girl who developed complete heart block before submission to surgery. The atrioventricular conduction axis was histologically discontinuous in the first case, but preserved and surrounded by hemorrhage in the second case. This study draws attention to the inherent vulnerability of the cardiac conduction axis which must also be recognized before surgical intervention.

Child↗
PubMed1985

Conduction system defects in three perinatal patients with arrhythmia.

The cardiac conduction systems of three patients who died in the perinatal period were studied histologically. Rhythm disturbances were observed in these patients immediately before death. The sinus node was notably hypoplastic without increase in fibrous content in all cases. The atrioventricular node was smaller than expected in all, and the entire atrioventricular conduction axis was small in two cases. This study supports the need for a detailed examination of the cardiac conduction system so as to provide a better understanding of the clinicoanatomical relation in the context of fatal perinatal arrhythmias.

Arrhythmias, Cardiac↗
PubMed1985

Congenital heart malformations in the first year of life--a necropsy study.

The hearts of 291 babies with congenital heart disease who died before the age of one were examined systematically by sequential segmental analysis to determine the lesions that were present. There was an abnormal connection between the cardiac segments in one third of cases. Patient ductus arteriosus, which is usually a common defect, was not an important finding at necropsy, whereas common arterial trunk (a rare defect) was found in 10%. The clinical and necropsy incidence of complete transposition was similar to that reported in earlier studies. The incidence of some lesions present at necropsy (for example Fallot's tetralogy) has altered over the past 10 years. A decline in the frequency with which a lesion is detected at necropsy may indicate advances in treatment or differences in classification. The presence of additional lesions influences the prognosis and subcategorisation within the major defect groupings gave some insight into the cause of death in many of the cases.

Age Factors↗
PubMed1985

Endocardectomy for the surgical treatment of endocardial fibrosis of the left ventricle.

Two patients with endomyocardial fibrosis of the left ventricle were treated by endocardectomy plus mitral valve replacement. In both cases the results of surgery were satisfactory. No consequences related to eosinophilia, which was present before operation in one of them, were noted. The poor prognosis of this progressive disease and the inefficiency of medical treatment compared with the good surgical results already reported from various centres encourage early operation for all patients with endomyocardial fibrosis who have symptoms. Because of the pathophysiology of the disease, endocardectomy should be attempted in all cases and anti-coagulant treatment continued for life.

Adult↗